BEIJING, Jan. 1 -- China on Monday formally started its fifth national economic census.

Some 2.1 million enumerators will go into businesses and communities to collect and register economic data in 1.16 million census areas over the next nearly four months, according to the National Bureau of Statistics (NBS).

China's national economic census takes place every five years.

The NBS carried out its preliminary work in the second half of last year, and the census is entering the stage of full implementation in 2024, with main tasks including on-site registration, spot checks of data quality, and the release of major data.

The fifth national economic census will comprehensively look into the development status, layout and efficiency of China's secondary and tertiary industries, according to Kang Yi, head of the NBS.

It will figure out the economic relations between sectors of the national economy, keep track of the progress of China's key economic tasks, and for the first time coordinate efforts to conduct an input-output survey, Kang said.